Microsoft Word is the most popular word-processing application on the planet, a fact often regretted by die-hard XML aficionados. Not us. It is a fine editor, and supports reasonably structured editing of content. Unfortunately, Microsoft don't make the most of these features.
Our YAWC Pro and YAWC Online products both include Word templates that use these features, such as showing the document map and the left-hand style window, adding shortcut keys for heading and list styles, and making it as easy as possible to apply structured markup.
Word 2003, due in mid-2003, has native XML support, which may eventually do away with the need for 3rd-party Word to XML converters. However, the good news for consultants like us is that XML will really move into the mainstream, providing lots of work, we hope!
If you have documents you want to convert today, we maintain a list of Word to XML converters, including our own modest offerings.